But the Better Business Bureau says "the warranty scam is still alive and well in 2016," and many car owners are now being targeted by new companies.

When Extended Warranty is a Good Idea

But from the "doesn't that stink" file, one instance where you may wish you bought an extended warranty: If you drop your smartphone and break it.

No warranty? You'll say "doesn't that stink".

With a $300 to $500 smartphone, extra coverage is well worth considering.

Bottom line: While some warranties can be worthwhile, be suspicious of all post card notices to renew your car's warranty. An extended warranty on your car can be worth having, for peace of mind, as long as you buy it from a reputable company, with a good Better Business Bureau report.

If you are confused, call your car's manufacturer or the dealer who sold it to you, to find out if it's legit or a case of don't waste your money.